Limiting fabric standards
Contents |
[edit] Introduction
The building regulations require that reasonable provision be made to limit heat gains and losses through the fabric of new buildings and works to existing buildings. The approved documents to the buildings regulations set out the limiting standards for the properties of the fabric elements of the building.
[edit] L1A, new dwellings, 2013 edition
| Roof | 0.2 W/(m^2K) |
| Wall | 0.3 W/(m^2K) |
| Floor | 0.25 W/(m^2K) |
| Party wall | 0.2 W/(m^2K) |
| Swimming pool basin | 0.25 W/(m^2K) |
| Windows, roof windows, glazed roof-lights, curtain walling and pedestrian doors | 2.0 W/(m^2K) |
| Air permeability | 10.0 m^3/(h.m^2) at 50 Pa |
[edit] L2A, new buildings other than dwellings, 2013 edition
| Roof | 0.25 W/(m^2K) |
| Wall | 0.35 W/(m^2K) |
| Floor | 0.25 W/(m^2K) |
| Swimming pool basin | 0.25 W/(m^2K) |
| Windows, roof windows, roof-lights, curtain walling and pedestrian doors | 2.2 W/(m^2K) |
| Vehicle access and similar large doors | 1.5 W/(m^2K) |
| High-usage entrance doors | 3.5 W/(m^2K) |
| Roof ventilators (inc. smoke vents) | 3.5 W/(m^2K) |
| Air permeability | 10.0 m^3/(h.m^2) at 50 Pa |
[edit] L1B and L2B, existing dwellings and existing buildings other than dwellings, 2010 editions
| New thermal elements | Retained thermal elements | |
| Wall | 0.28 W/(m^2K) | |
| Pitched roof – insulation at ceiling level | 0.16 W/(m^2K) | 0.16 W/(m^2K) |
| Pitched roof – insulation at rafter level | 0.18 W/(m^2K) | 0.18 W/(m^2K) |
| Flat roof or roof with integral insulation | 0.18 W/(m^2K) | 0.18 W/(m^2K) |
| Floors | 0.22 W/(m^2K) | 0.25 W/(m^2K) |
| Swimming Pool basin | 0.25 W/(m^2K) | |
| Wall – cavity insulation | 0.55 W/(m^2K) | |
| Wall – external or internal insulation | 0.30 W/(m^2K) |
NB Approved Document C gives limiting values for individual elements to minimise the risk of condensation.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
- 2013 changes to the approved documents for part L of the building regulations
- Approved documents.
- Building Regulations.
- PA ratio.
- Part L.
- U-value.
[edit] External references
- Approved Document L1A: Conservation of fuel and power in new dwellings, 2013 edition.
- Approved Document L2A: Conservation of fuel and power in new buildings other than dwellings, 2013 edition.
Featured articles and news
From the sinister Carceri d’Invenzione to the triple portrait of Sir Watkin Williams-Wynn and his Grand Tour travelling companions.
Design freeze: a quality perspective
Progressively freezing a design helps ensure it meets the specification when built.
BSRIA launch the 5th edition of the Design Framework for Building Services (BG 6/2018).
Stella Rimmington famously said the construction industry was just as tricky as the KGB.
CSCS
Construction site visitor cards are to be withdrawn.
3 WTC opens, RSHP’s first built project in New York.
We have a lots of articles about lifts - this introduction is a good place to start.
BREEAM ES and SIMA present for the first time a reproduction of a sustainable home.
How's that for customer satisfaction? The results of our user survey are in.
One of the most significant barriers to realising true value from digital transformation.
A great reference text for dipping into, and an absorbing read.
Owen Hatherley pulls no punches in our interview about his new book 'Trans-Europe Express' and much more.